Tractor with monitoring system

ABSTRACT

A tractor includes a cab mounted analysis/display unit ( 1 ) connected to a number of on-board sensors for detecting speed, fuel flow, etc and also capable of receiving data input manually or via a data carrier. The unit ( 1 ) is also connected to an on-board GPS navigation system ( 24 ), and includes means for generating maps of tractor-related parameters and/or parameters derived therefrom. The math usefulness of the system is in derby “on the go” maps of cost related data for a given field operation. Cost maps for cumulative operations and maps of gross profit margin are possible by adding “on the go” generated cost data to previously generated cost and/or yield data as the tractor performs an operation in a field.

This application is a continuation of 09/043982 filed Mar. 19, 1999 andnow U.S. Pat. No. 6,195,604 which is a 371 PCT/GB96/02216 filedSeptember 1996.

BACKGROUND OF THE INVENTION

The present invention relates to a tractor with a monitoring system andmeans for locating the tractor.

It is known to display sensed parameters on an electronic tractormonitoring system. It is also known to provide a location system, eg aGPS satellite location system, in a combine harvester and to combineinformation from such a system with, for example, a continuous signalrepresentative of the rate of flow of grain entering the harvester,thereby to produce a “yield map” showing grain yield as a map over anarea where the combine harvester has travelled.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a tractor with animproved monitoring system.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and details of the present invention will be apparentfrom the following specific description given by way of example onlywith reference to the accompanying drawings in which:

FIG. 1 is a schematic side sectional view of a tractor in accordancewith the invention, and

FIG. 2 is an example map produced in accordance with the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring firstly to FIG. 1, a tractor in accordance with the inventioncomprises the standard elements of an engine E, gearbox G/B, PTO outputshaft P, and three point linkage L.

Situated in the tractor cab is an electronic monitoring systemanalasys/display unit 1 into which run lines from a number of electronicsensors an the tractor.

A fuel tank 2 is housed at the rear of tractor and a fuel line 3 passesfrom the tank to the engine E via a fuel flow sensor 4. An electronicoutput from the fuel flow sensor 4 is connected via line 5 to thedisplay unit 1.

A further sensor 6 for detecting engine speed, is of the magneticinductance type and is mounted adjacent a gear 7 which drives the engineoil pump. The electronic output of the sensor 6 is connected via a line9 to the display unit 1.

A radar speed sensor 10 is mounted underneath the tractor for detectingactual speed over the ground. The sensor 10 is connected via a line 11to the display unit 1.

A further magnetic inductance sensor 12 is associated with the crownwheel 13 on the rear axle of the tractor for detecting “theoretical”forward speed (ie forward speed with no wheel slip). The electronicoutput of the inductance sensor 12 is connected via a line 14 to thedisplay unit 1.

A further magnetic inductance sensor 15 is associated with the powertake off gearbox 16 and detects the PTO speed. The electronic output ofthe sensor 15 is connected via a line 17 to the display unit 1.

The three point linkage L has both draft force and position sensorsassociated with the top link joint, the sensors being commonly shown inFIG. 1 by the numeral 18. The force sensor is of known type, taking theform of a joint pin incorporating strain gauges. The electronic outputfrom the force sensor is connected via a signal line 19 to the displayunit 1. The position of the linkage, that is to say its height, ismeasured by a rotary potentiometer associated with the top link joint.The potentiometer is connected via a line 20 to the display unit 1.

Situated in the tractor cab is an electronic linkage control unit 21 ofknown type, which includes a linkage lift/lower control 22. Theelectronic linkage control unit is connected via a line 23 to thedisplay unit 1.

The tractor is fitted with a GPS satellite navigation system 24 which isconnected via signal line or lines 25 to the display unit 1.

Finally, a socket 26 is provided for receive an input signal from animplement connected to the tractor, and this is connected via a line 27to the display unit 1.

The display unit 1 includes a touch sensitive screen 28 via which anumber of functions connected with monitoring/displaying tractorparameters may be selected and controlled. The unit 1 also allows thevarious parameters as sensed on the tractor, as well as informationderived therefrom, to be displayed on the screen 28, or alternativelyoutput on to a data carrier inserted into a slot 29, or alternativelyoutput in printed form on a paper tape output from slot 30.

The display unit 1 is essentially also a data processing unit, as willbe appreciated from what has been said above. The unit includes anintegral clock, a microprocessor and electronic memory. Software toenable the functions described above to be performed, is stored andimplemented by the unit 1. The unit 1 is programmed to accept the inputof certain parameters either manually via the touch screen or via a datacarrier, such as a magnetic disk or PCMIA card inserted in to the slot29. The unit 1 is also programmed to receive information from the GPSnavigation system 24 and combine this with any of the parameters sensedby the various sensors around the tractor together with any relevantdata input manually or via a data carrier. In this way, the unitproduces maps of tractor speed information which may be combined withmanually input information.

At its simplest level, the system may be used to generate, for example,a map of fuel used per hectare when performing an operation with a soilpenetrating implement. To generate such a map, the unit 1 would employinformation from the GPS unit 24, from the fuel flow sensor 4, from thetractor speed sensor 10 and from a manual input representative of thewidth of the implement being used, and thus the width of the strip offield processed on any given run of the tractor. The unit 1 would alsouse the input from the electronic linkage control 21, which includes anindication of whether the implement is in a raised or lowered conditionand therefore out of work or in work. Lastly, the unit 1 would useinformation from its integral clock.

A realistic map of fuel used per hectare may then be generated bycontinuously sensing the fuel flow data from the sensor 4 andcontinuously calculating the rate at which area is being covered(derived from speed and implement width), and sampling these parametersrepeatedly at known positions of the tractor (from the GPS). At eachsampling point, a value for fuel used since the last sample is dividedby hectares covered since the last sample and this fuel/hectare valuecorrelated to tractor position. At the end of each run, the linkage willof course be raised to bring the implement out of work and this factwill be recognised by the unit 1 from the signal on line 23 from theelectronic linkage control 21 The amount of fuel used from the time theimplement is lifted out of work until the time it is returned into workat the start of the next run can be retrospectively added to the seriesof fuel/hectare values for the previous run, being apportioned equallyover all the readings. Alternatively, the value for fuel used can bestored and then apportioned equally over the readings for the next run.Either way, the fuel used per hectare figure for a narrow portion offield with very short runs will reflect the fact that the tractor spendsa relatively large percentage of its time turning on headlands.

In a simple modification of the above process, the fuel used per hectarefigure can be amended to a fuel cost per hectare figure by the simpleincorporation of a manually input unit fuel cost figure.

It will be appreciated that the operation described above involvesautomatic sensing of lifting and lowering of the tractor linkage at eachend of a run (simply by noting the position of the lift/lower switch22). Alternatively, in an operation where the linkage is not lifted andlowered at the end/start of each run (eg spreading fertiliser), afurther manual input can be provided in the form of an icon on the touchscreen which is touched at the end and the start of each run.Alternatively, this information could be input directly from theimplement via the socket 26 and line 27. There could also be some formof connection between the unit 1 and a cab mounted implement controlunit to achieve the same result.

The above described operation is a novel and relatively simple way ofproviding an indication of the cost of performing a process on a field,showing how that cost is distributed across the field. A more useful wayof doing this is to combine all or at least most of the sensed tractorparameters described above with data input manually or via a datacarrier as follows:

1 cost of tractor driver per hour;

2 depreciation of tractor per hour;

3 maintenance cost of tractor per hour;

4 a parameter representative of tractor tire cost per hour;

5 a parameter representative of soil type.

The cost of a driver's wages, depreciation and maintenance need noexplanation; their effect on the cost of the tractor operation isself-explanatory. Actual tractor tire wear is influenced by a number offactors, so a basic tire cost parameter is used representing purchasecost depreciated over an average tyre lifetime. This is then modified bythe unit 1 according to the soil type parameter, since certain types ofsoil will wear a tire quicker than others. Other factors used tocalculate actual tyre wear, and therefore cost, are wheel slip, which isdirectly calculated from the actual speed sensor 10 and theoreticalspeed sensor 12, draft force from the draft force sensor 18 assuming asoil penetrating implement is attached, and forward speed from thesensor 10.

A possibility with this system is the generation of cumulative treatmentcost maps. A previously generated cost map for a given treatment, egploughing a field, may be inserted into the unit 1, and then informationrelating to the cost of a second process added as the second process isperformed. If this is done for every treatment applied to the field, areasonably true indication of the cost of growing that crop, as mappedacross the fields may be produced. In addition, the previous year'syield in the form of a map on a data carrier may be input into the unit1 together with a manually input figure representative of the value ofthe crop per tonne. In this way, a “gross margin” map can be producedwhich gives a direct indication of which parts of the field are moreprofitable than others and which may show that some parts of the fieldare actually making a loss.

For some field operations, the cost is going to be relatively uniformand mapping, therefore, not really worthwhile. In this case, a manuallyinput constant value of cost/hectare may be used for one or more of thefield processes, when generating a cumulative cost map as describedabove.

A useful variation of the above is to produce a map of “fieldefficiency”, that is to say the percentage of time spent working thefield as opposed to turning on headlands, combined with a constant valuefor cost/hour. Cost/hectare is then calculated “on the go” during a run,based on speed and implement width, and sampled at intervals for mappingas with the previously described mapping processes. At the and of eachrun, the cost of the time spent turning before starting the next run iscalculated and averaged over the sampled values (or alternatively storedand then averaged over the sampled values for the next run). Arefinement of this would be to have different constant cost/hour valuesfor “in work” and “out of work”.

A map of field efficiency alone can also be very useful, ie a map simplyshowing an efficiency value for each tractor run. Such a map may be usedto design field shapes and/or the direction of ploughing etc.

It should be noted that field efficiency will vary between processes;the time spent on headlands will generally be much more significant fora fast process than a slow one.

For any map of cost related data, field efficiency is one of the majorfactors contributing to cost and may be used in many different ways.

Although mapping cost related parameters is very useful, this inventionis not restricted to the mapping of cost related parameters. A mapshowing one of the tractor sensed parameters mentioned above asdistributed over a field during a given treatment process can be usefulin its own right. For example, the variation of PTO speed during afertiliser spreading process can be useful to monitor since the map mayshow that PTO speed dropped to an unacceptable level for part of thetime, in which case the spread of fertiliser may have been inadequateand may require subsequent treatment to ensure that sufficientfertiliser is applied. Such a map could be derived using data eitherfrom the PTO speed senior or engine speed sensor, since the PTO gearratio will be a known constant.

Another parameter which could usefully be mapped during, say, aploughing operation, is linkage height. If the linkage control is indraft control mode, as is conventional for a ploughing operation, thelinkage height will be automatically adjusted to maintain draft forceconstant. Consequently, a map of linkage height gives an indication ofwhere areas of difficult soil are.

For any of the types of map described above, the presentation of the mapwill be most useful if a certain shading or colour is given to each areaof the field map where the mapped parameter falls in a given range. Anexample of this is shown in FIG. 2 where three ranges of mappedparameter are used, A, B and C. The actual parameter shown on this mapis unimportant—it could be any of those described above or any number ofother possibilities.

The software with which the unit 1 is programmed has the facility toallow selection of ranges for creating a map of the form shown in FIG.2.

What is claimed is:
 1. An apparatus for mapping the performance of an agricultural tractor during operation in an agricultural field comprising: a sensor that generates a signal that is representative of an operating characteristic of the agricultural tractor; and a controller that is responsive to said signal from said sensor and that generates a performance map of the performance of the agricultural tractor as a function of an area in the agricultural field in which the agricultural tractor is operated.
 2. The apparatus defined in claim 1 wherein said sensor is an engine sensor that generates a signal that is representative of an operating characteristic of an engine provided on the agricultural tractor.
 3. The apparatus defined in claim 2 wherein said engine sensor is a sensor that generates a signal that is representative of the speed of the engine.
 4. The apparatus defined in claim 2 wherein said engine sensor is a sensor that generates a signal that is representative of the amount of fuel supplied to the engine.
 5. The apparatus defined in claim 1 wherein said sensor is a speed sensor that generates a signal that is representative of the speed of the tractor.
 6. The apparatus defined in claim 1 wherein said sensor is a power take off sensor that generates a signal that is representative of an operating characteristic of a power take off provided on the agricultural tractor.
 7. The apparatus defined in claim 6 wherein said power take off sensor is a sensor that generates a signal that is representative of the speed of the power take off.
 8. The apparatus defined in claim 1 wherein said sensor is a linkage sensor that generates a signal that is representative of an operating characteristic of a three point linkage provided on the agricultural tractor.
 9. The apparatus defined in claim 8 wherein said linkage sensor is a sensor that generates a signal that is representative of the draft force of the three point linkage.
 10. The apparatus defined in claim 8 wherein said linkage sensor is a sensor that generates a signal that is representative of the position of the three point linkage.
 11. The apparatus defined in claim 1 wherein said sensor is a position sensor that generates a signal that is representative of the position of the tractor in the agricultural field.
 12. The apparatus defined in claim 11 wherein said position sensor is a global satellite navigation system.
 13. The apparatus defined in claim 1 further including an actual speed sensor that generates a signal that is representative of the actual speed of the agricultural tractor over ground, said controller being responsive to said signals from said sensor and said actual speed sensor and generating the performance map.
 14. The apparatus defined in claim 1 further including a theoretical speed sensor that generates a signal that is representative of the theoretical speed of the agricultural tractor over ground if no wheel slip is occurring, said controller being responsive to said signals from said sensor and said theoretical speed sensor and generating the performance map.
 15. The apparatus defined in claim 1 further including a manual input device that generates a signal that is representative of a parameter, said controller being responsive to said signals from said sensor and said manual input device for generating the performance map. 